2008-01-13 Neal H. Walfield <neal@gnu.org>

	* backtrace.c: New file.
	* Makefile.am (libc_parts_a_SOURCES): Add backtrace.c.

	* assert.h (assertx): Print a back trace.

4 files changed, 87 insertions, 18 deletions

diff --git a/libc-parts/ChangeLog b/libc-parts/ChangeLog
index 3fbe735..15f67c6 100644
--- a/libc-parts/ChangeLog
+++ b/libc-parts/ChangeLog
@@ -1,3 +1,10 @@
+2008-01-13  Neal H. Walfield  <neal@gnu.org>
+
+	* backtrace.c: New file.
+	* Makefile.am (libc_parts_a_SOURCES): Add backtrace.c.
+
+	* assert.h (assertx): Print a back trace.
+
 2008-01-08  Neal H. Walfield  <neal@gnu.org>
 
 	* setjmp.h: New file.
diff --git a/libc-parts/Makefile.am b/libc-parts/Makefile.am
index f259674..4b12a96 100644
--- a/libc-parts/Makefile.am
+++ b/libc-parts/Makefile.am
@@ -32,7 +32,7 @@ libc_parts_a_SOURCES = $(ARCH_SOURCES) 				\
 	assert.h ctype.h c-ctype.h c-ctype.c			\
 	errno.h errno.c						\
 	strtol.c strtoll.c strtoul.c strtoull.c			\
-	setjmp.h
+	setjmp.h backtrace.c
 
 # For the following routines we want to take the possibly optimized
 # versions from the target's GNU C library, rather than duplicating
diff --git a/libc-parts/assert.h b/libc-parts/assert.h
index 8ce8e53..0bdb7ec 100644
--- a/libc-parts/assert.h
+++ b/libc-parts/assert.h
@@ -1,5 +1,5 @@
 /* assert.h - Assert declaration for libc-parts.
-   Copyright (C) 2003, 2005, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2005, 2007, 2008 Free Software Foundation, Inc.
    Written by Neal H. Walfield <neal@gnu.org>.
 
    This file is part of the GNU Hurd.
@@ -40,22 +40,32 @@ int printf (const char *fmt, ...);
 # ifndef NDEBUG
 #include <l4/thread.h>
 
-#  define assertx(__ax_expr, __ax_fmt, ...)			\
-  do {								\
-    extern const char program_name[];				\
-    if (! (__ax_expr))						\
-      {								\
-	printf ("%s (%x):%s:%s:%d: %s failed",			\
-		program_name, l4_myself (),			\
-		__FILE__, __func__, __LINE__,			\
-		#__ax_expr);					\
-	if ((__ax_fmt) && *(__ax_fmt))				\
-	  {							\
-	    printf (": " __ax_fmt, ##__VA_ARGS__);		\
-	  }							\
-	printf ("\n");						\
-	for (;;);						\
-      }								\
+#  define assertx(__ax_expr, __ax_fmt, ...)				\
+  do {									\
+    extern const char program_name[];					\
+    if (! (__ax_expr))							\
+      {									\
+	printf ("%s (%x):%s:%s:%d: %s failed",				\
+		program_name, l4_myself (),				\
+		__FILE__, __func__, __LINE__,				\
+		#__ax_expr);						\
+	if ((__ax_fmt) && *(__ax_fmt))					\
+	  {								\
+	    printf (": " __ax_fmt, ##__VA_ARGS__);			\
+	  }								\
+	printf ("\n");							\
+									\
+	extern int backtrace (void **array, int size);			\
+									\
+	void *a[10];							\
+	int count = backtrace (a, sizeof (a) / sizeof (a[0]));		\
+	int i;								\
+	for (i = 0; i < count; i ++)					\
+	  printf ("Backtrace: %p%s", a[i], i == count - 1 ? "" : " -> "); \
+	printf ("\n");							\
+									\
+	for (;;);							\
+      }									\
   } while (0)
 
 #  define assert(__a_expr)				\
diff --git a/libc-parts/backtrace.c b/libc-parts/backtrace.c
new file mode 100644
index 0000000..293dad0
--- /dev/null
+++ b/libc-parts/backtrace.c
@@ -0,0 +1,52 @@
+/* backtrace.c - Gather a backtrace.
+   Copyright (C) 2008 Free Software Foundation, Inc.
+   Written by Neal H. Walfield <neal@gnu.org>.
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#define RA(level)						\
+  if (level < size && __builtin_return_address ((level) + 1))	\
+    *array = __builtin_return_address ((level) + 1);		\
+  else								\
+    return level;
+
+int
+backtrace (void **array, int size)
+{
+  RA(0);
+  RA(1);
+  RA(2);
+  RA(3);
+  RA(4);
+  RA(5);
+  RA(6);
+  RA(7);
+  RA(9);
+  RA(10);
+  RA(11);
+  RA(12);
+  RA(13);
+  RA(14);
+  RA(15);
+  RA(16);
+  RA(17);
+  RA(18);
+  RA(19);
+  RA(20);
+  return 20;
+}